RDU to DEN flight delays
Raleigh/Durham, NC (RDU) Denver, CO (DEN) · 1,436 miles
1,771 flights · January 2025 – August 2026 · US Bureau of Transportation Statistics
79.99%
Arrived on time
Within 15 minutes of schedule
0.85%
Cancelled
Share of scheduled flights
68 min
When late, late by
Average across delayed arrivals
15 min
Delay per flight
Averaged over every flight flown
What the record says about this route
Which airline you fly changes the odds here. United Airlines arrived on time 12.3 points more often than Southwest Airlines over the same period on the same route — same airports, same weather, same air traffic control. A gap that survives all of that is about how the two airlines are run.
The season swings this route hard. In May it ran 22.5 points more punctual than in July — a difference bigger than the one between the best and worst airlines on most routes. If the date is flexible, it is worth more than the carrier.
The route has been getting better. The later months in the record run 9.1 points more punctual than the earlier ones, which usually means a schedule that was too tight has been given more room.
The Raleigh/Durham to Denver route sits close to the middle of the record — neither notably punctual nor notably late.
Which airline should you fly on this route?
Over January 2025 – August 2026, United Airlines arrived on time most often on RDU to DEN. Southwest Airlines was late most often. Flights ran closest to schedule in May and worst in July.
Every airline on RDU to DEN
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| United Airlines | 776 | 86.33% | 0.64% | 90 min | B |
| Southwest Airlines | 709 | 74.04% | 0.85% | 55 min | D |
| Frontier Airlines | 286 | 77.5% | 1.4% | 71 min | C |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
DEN to RDU Denver back to Raleigh/Durham 75.19% on time COther routes from Raleigh/Durham
Common questions
Are flights from Raleigh/Durham to Denver usually delayed?
79.99% of flights on the RDU to DEN route arrived within 15 minutes of schedule, so roughly 2 in every ten arrived late. That is about the same as the average route in this record.
Which airline is most on time from Raleigh/Durham to Denver?
United Airlines, at 86.33% on time across 776 flights. The least punctual on the route was Southwest Airlines at 74.04%.
How often are RDU to DEN flights cancelled?
0.85% of scheduled flights did not operate — about 9 in every thousand. That is in the normal range.
What is the best month to fly Raleigh/Durham to Denver?
May, when 89% of flights arrived on time. The worst was July at 66.5%.
When RDU to DEN flights are late, how late are they?
About 68 minutes on average across the flights that arrived more than 15 minutes behind schedule.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on RDU to DEN during January 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →